RESUMEN
BACKGROUND: Pretreatment serum squamous cell carcinoma antigen (SCCA) is a prognostic biomarker in women with cervical cancer. SCCA has not been evaluated as an early indicator of response to chemoradiation therapy (CRT). The molecular role of the two SCCA isoforms, SCCA1 (SERPINB3) and SCCA2 (SERPINB4), in cervical cancer is unknown. We hypothesised that changes in serum SCCA during definitive CRT predicts treatment response, and that SCCA1 mediates radiation resistance. METHODS: Patients treated with definitive CRT for cervical squamous carcinoma with serum SCCA measured were included. SCCA immunohistochemistry was performed on tumour biopsies. Post-treatment FDG-PET/CT, recurrence, and overall survival were recorded. Radiation response of cervical tumour cell lines after SCCA1 expression or CRISPR/Cas9 knockout was evaluated by clonogenic survival assay. RESULTS: Persistently elevated serum SCCA during definitive CRT was an independent predictor of positive post-therapy FDG-PET/CT (P=0.043), recurrence (P=0.0046) and death (P=0.015). An SCCA1-expressing vector increased radioresistance, while SCCA knock out increased radiosensitivity of cervical tumour cell lines in vitro. CONCLUSIONS: Early response assessment with serum SCCA is a powerful prognostic tool. These findings suggest that escalation of therapy in patients with elevated or sustained serum SCCA and molecular targeting of SCCA1 should be considered.
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Antígenos de Neoplasias/sangre , Antígenos de Neoplasias/metabolismo , Biomarcadores de Tumor/sangre , Carcinoma de Células Escamosas/terapia , Quimioradioterapia/métodos , Serpinas/sangre , Serpinas/metabolismo , Neoplasias del Cuello Uterino/terapia , Adulto , Anciano , Anciano de 80 o más Años , Antígenos de Neoplasias/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/metabolismo , Línea Celular Tumoral , Cisplatino/administración & dosificación , Cisplatino/uso terapéutico , Fraccionamiento de la Dosis de Radiación , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Persona de Mediana Edad , Serpinas/genética , Análisis de Supervivencia , Resultado del Tratamiento , Regulación hacia Arriba , Neoplasias del Cuello Uterino/sangre , Neoplasias del Cuello Uterino/metabolismoRESUMEN
Xenin-25 (Xen) is a neurotensin-related peptide secreted by a subset of glucose-dependent insulinotropic polypeptide (GIP)-producing enteroendocrine cells. In animals, Xen regulates gastrointestinal function and glucose homeostasis, typically by initiating neural relays. However, little is known about Xen action in humans. This study determines whether exogenously administered Xen modulates gastric emptying and/or insulin secretion rates (ISRs) following meal ingestion. Fasted subjects with normal (NGT) or impaired (IGT) glucose tolerance and Type 2 diabetes mellitus (T2DM; n = 10-14 per group) ingested a liquid mixed meal plus acetaminophen (ACM; to assess gastric emptying) at time zero. On separate occasions, a primed-constant intravenous infusion of vehicle or Xen at 4 (Lo-Xen) or 12 (Hi-Xen) pmol · kg(-1) · min(-1) was administered from zero until 300 min. Some subjects with NGT received 30- and 90-min Hi-Xen infusions. Plasma ACM, glucose, insulin, C-peptide, glucagon, Xen, GIP, and glucagon-like peptide-1 (GLP-1) levels were measured and ISRs calculated. Areas under the curves were compared for treatment effects. Infusion with Hi-Xen, but not Lo-Xen, similarly delayed gastric emptying and reduced postprandial glucose levels in all groups. Infusions for 90 or 300 min, but not 30 min, were equally effective. Hi-Xen reduced plasma GLP-1, but not GIP, levels without altering the insulin secretory response to glucose. Intense staining for Xen receptors was detected on PGP9.5-positive nerve fibers in the longitudinal muscle of the human stomach. Thus Xen reduces gastric emptying in humans with and without T2DM, probably via a neural relay. Moreover, endogenous GLP-1 may not be a major enhancer of insulin secretion in healthy humans under physiological conditions.
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Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Vaciamiento Gástrico/efectos de los fármacos , Hipoglucemiantes/uso terapéutico , Neurotensina/uso terapéutico , Periodo Posprandial , Adulto , Biomarcadores/sangre , Glucemia/metabolismo , Péptido C/sangre , Estudios Cruzados , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Esquema de Medicación , Femenino , Glucagón/sangre , Péptido 1 Similar al Glucagón/sangre , Humanos , Hipoglucemiantes/administración & dosificación , Infusiones Intravenosas , Insulina/sangre , Masculino , Persona de Mediana Edad , Missouri , Neurotensina/administración & dosificación , Receptores de Neurotensina/efectos de los fármacos , Receptores de Neurotensina/metabolismo , Factores de Tiempo , Resultado del TratamientoRESUMEN
This prospective crossover study aimed to investigate the effect of binaural beat therapy music on soccer player performance. Between July 2023 and December 2023, 45 athletes (31 females/14 males, mean age = 20.47 ± 0.99) wore Bluetooth earphones through which one of the following was given during initial 20 min warm-up exercises before undergoing repeated sprint ability tests: no music/fast-tempo music/fast-tempo music with background binaural beat therapy music. Heart rate change after warm-up exercises/repeated sprint ability (RSA) tests and the time to finish RSA tests were recorded. Despite no significant difference in heart rate increase after warm-up between the two genders regardless of intervention, larger increases after RSA tests were found in males following any of the three interventions (all p < 0.01) with the most notable difference observed after fast-tempo music (p < 0.0001). A significant effect size (r = 0.2) correlated with fast-tempo music during warm-up in either gender. Binaural beat therapy music during warm-up reached a significant effect size only when all participants were considered, suggesting limited benefits.
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Radiotherapy is a commonly used cancer treatment; however, patients with high serum squamous cell carcinoma antigen (SCCA1/SERPINB3) are associated with resistance and poor prognosis. Despite being a strong clinical biomarker, the modulation of SERPINB3 in tumor immunity is poorly understood. We investigated the microenvironment of SERPINB3 high tumors through RNAseq of primary cervix tumors and found that SERPINB3 was positively correlated with CXCL1/8, S100A8/A9 and myeloid cell infiltration. Induction of SERPINB3 in vitro resulted in increased CXCL1/8 and S100A8/A9 production, and supernatants from SERPINB3-expressing cultures attracted monocytes and MDSCs. In murine tumors, the orthologue mSerpinB3a promoted MDSC, TAM, and M2 macrophage infiltration contributing to an immunosuppressive phenotype, which was further augmented upon radiation. Radiation-enhanced T cell response was muted in SERPINB3 tumors, whereas Treg expansion was observed. A STAT-dependent mechanism was implicated, whereby inhibiting STAT signaling with ruxolitinib abrogated suppressive chemokine production. Patients with elevated pre-treatment serum SCCA and high pSTAT3 had increased intratumoral CD11b+ myeloid cell compared to patients with low SCCA and pSTAT3 cohort that had overall improved cancer specific survival after radiotherapy. These findings provide a preclinical rationale for targeting STAT signaling in tumors with high SERPINB3 to counteract the immunosuppressive microenvironment and improve response to radiation.
RESUMEN
Patients with cancer who have high serum levels of squamous cell carcinoma antigen 1 (SCCA1, now referred to as SERPINB3) commonly experience treatment resistance and have a poor prognosis. Despite being a clinical biomarker, the modulation of SERPINB3 in tumor immunity is poorly understood. We found positive correlations of SERPINB3 with CXCL1, CXCL8 (CXCL8/9), S100A8, and S100A9 (S100A8/A9) myeloid cell infiltration through RNA-Seq analysis of human primary cervical tumors. Induction of SERPINB3 resulted in increased CXCL1/8 and S100A8/A9 expression, which promoted monocyte and myeloid-derived suppressor cell (MDSC) migration in vitro. In mouse models, Serpinb3a tumors showed increased MDSC and tumor-associated macrophage (TAM) infiltration, contributing to T cell inhibition, and this was further augmented upon radiation. Intratumoral knockdown (KD) of Serpinb3a resulted in tumor growth inhibition and reduced CXCL1 and S100A8/A expression and MDSC and M2 macrophage infiltration. These changes led to enhanced cytotoxic T cell function and sensitized tumors to radiotherapy (RT). We further revealed that SERPINB3 promoted STAT-dependent expression of chemokines, whereby inhibition of STAT activation by ruxolitinib or siRNA abrogated CXCL1/8 and S100A8/ A9 expression in SERPINB3 cells. Patients with elevated pretreatment SCCA levels and high phosphorylated STAT3 (p-STAT3) had increased intratumoral CD11b+ myeloid cells compared with patients with low SCCA levels and p-STAT3, who had improved overall survival after RT. These findings provide a preclinical rationale for targeting SERPINB3 in tumors to counteract immunosuppression and improve the response to RT.
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Calgranulina A , Serpinas , Ratones , Animales , Humanos , Calgranulina A/genética , Calgranulina B/genética , Serpinas/genética , Quimiocinas/metabolismoRESUMEN
Xenin-25 (Xen) is a 25 amino acid neurotensin-related peptide reportedly produced with glucose-dependent insulinotropic polypeptide (GIP) by a subset of K cells in the proximal gut. We previously showed exogenously administered Xen, with GIP but not alone, increases insulin secretion in humans and mice. In mice, this effect is indirectly mediated via a central nervous system-independent cholinergic relay in the periphery. Xen also delays gastric emptying, reduces food intake, induces gall bladder contractions, and increases gut motility and secretion from the exocrine pancreas, suggesting that some effects of Xen could be mediated by myenteric neurons (MENs). To determine whether Xen activates these neurons, MENs were isolated from guinea pig proximal small intestines. Cells expressed neuronal markers and exhibited typical neuron-like morphology with extensive outgrowths emanating from cell bodies. Cytosolic free Ca(2+) levels ([Ca(2+)](i)) were measured using Fura-2. ATP/UTP, KCl, and forskolin increased [Ca(2+)](i) in 99.6%, 92%, and 23% of the MENs imaged, respectively, indicating that they are functional and activated by nucleotide receptor signaling, direct depolarization, and cAMP. [Ca(2+)](i) increased in only 12.7% of MENs treated with Xen. This rise was blocked by pretreatment with EGTA, diazoxide, SR48692, and neurotensin. Thus the Xen-mediated increase in [Ca(2+)](i) involves influx of extracellular Ca(2+) and activation of neurotensin receptor-1 (NTSR1). Xen also increased acetylcholine release from MENs. Amylin, produced by ß-and enteroendocrine cells, delays gastric emptying and increased [Ca(2+)](i) almost exclusively in Xen-responsive MENs. Immunohistochemistry demonstrated NTSR1 expression in human duodenal MENs. Thus myenteric rather than central neurons could mediate some effects of Xen and amylin.
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Acetilcolina/metabolismo , Calcio/metabolismo , Intestino Delgado/inervación , Intestino Delgado/metabolismo , Plexo Mientérico/metabolismo , Neuronas/metabolismo , Neurotensina/metabolismo , Animales , Células Cultivadas , Citosol , Femenino , Cobayas , Humanos , Intestino Delgado/efectos de los fármacos , Masculino , Plexo Mientérico/citología , Neurotensina/farmacología , Receptores de Neurotensina/metabolismoRESUMEN
The endogenous lysosomal cysteine protease inhibitor SERPINB3 (squamous cell carcinoma antigen 1, SCCA1) is elevated in patients with cervical cancer and other malignancies. High serum SERPINB3 is prognostic for recurrence and death following chemoradiation therapy. Cervical cancer cells genetically lacking SERPINB3 are more sensitive to ionizing radiation (IR), suggesting this protease inhibitor plays a role in therapeutic response. Here we demonstrate that SERPINB3-deficient cells have enhanced sensitivity to IR-induced cell death. Knock out of SERPINB3 sensitizes cells to a greater extent than cisplatin, the current standard of care. IR in SERPINB3 deficient cervical carcinoma cells induces predominantly necrotic cell death, with biochemical and cellular features of lysoptosis. Rescue with wild-type SERPINB3 or a reactive site loop mutant indicates that protease inhibitory activity is required to protect cervical tumor cells from radiation-induced death. Transcriptomics analysis of primary cervix tumor samples and genetic knock out demonstrates a role for the lysosomal protease cathepsin L in radiation-induced cell death in SERPINB3 knock-out cells. These data support targeting of SERPINB3 and lysoptosis to treat radioresistant cervical cancers.
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Antígenos de Neoplasias/genética , Catepsina L/antagonistas & inhibidores , Muerte Celular , Radiación Ionizante , Serpinas/genética , Neoplasias del Cuello Uterino/tratamiento farmacológico , Animales , Antígenos de Neoplasias/metabolismo , Línea Celular Tumoral , Femenino , Humanos , Ratones , Células Neoplásicas Circulantes/efectos de los fármacos , Serpinas/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Lysosomal membrane permeabilization (LMP) and cathepsin release typifies lysosome-dependent cell death (LDCD). However, LMP occurs in most regulated cell death programs suggesting LDCD is not an independent cell death pathway, but is conscripted to facilitate the final cellular demise by other cell death routines. Previously, we demonstrated that Caenorhabditis elegans (C. elegans) null for a cysteine protease inhibitor, srp-6, undergo a specific LDCD pathway characterized by LMP and cathepsin-dependent cytoplasmic proteolysis. We designated this cell death routine, lysoptosis, to distinguish it from other pathways employing LMP. In this study, mouse and human epithelial cells lacking srp-6 homologues, mSerpinb3a and SERPINB3, respectively, demonstrated a lysoptosis phenotype distinct from other cell death pathways. Like in C. elegans, this pathway depended on LMP and released cathepsins, predominantly cathepsin L. These studies suggested that lysoptosis is an evolutionarily-conserved eukaryotic LDCD that predominates in the absence of neutralizing endogenous inhibitors.
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Antígenos de Neoplasias/genética , Muerte Celular , Células Epiteliales/fisiología , Serpinas/genética , Animales , Antígenos de Neoplasias/metabolismo , Línea Celular Tumoral , Humanos , Ratones , Serpinas/metabolismoRESUMEN
Synapse remodeling is a widespread and fundamental process that underlies the formation of neuronal circuitry during development and in adaptation to physiological and/or environmental changes. However, the mechanisms of synapse remodeling are poorly understood. Synapses at the neuromuscular junction (NMJ) in Drosophila larvae undergo dramatic and extensive remodeling during metamorphosis to generate adult-specific synapses. To explore the molecular and cellular processes of synapse elimination, we performed confocal microscopy, live imaging, and electron microscopy (EM) of NMJ synapses during the early stages of metamorphosis in Drosophila in which the expressions of selected genes were genetically altered. We report that the localization of the postsynaptic scaffold protein Disc large (Dlg) becomes diffuse first and then undetectable, as larval muscles undergo histolysis, whereas presynaptic vesicles aggregate and are retrogradely transported along axons in synchrony with the formation of filopodia-like structures along NMJ elaborations and retraction of the presynaptic plasma membrane. EM revealed that the postsynaptic subsynaptic reticulum vacuolizes in the early stages of synapse dismantling concomitant with diffuse localization of Dlg. Ecdysone is the major hormone that drives metamorphosis. Blockade of the ecdysone signaling specifically in presynaptic neurons by expression of a dominant-negative form of ecdysone receptors delayed presynaptic but not postsynaptic dismantling. However, inhibition of ecdysone signaling, as well as ubiquitination pathway or apoptosis specifically in postsynaptic muscles, arrested both presynaptic and postsynaptic dismantling. These results demonstrate that presynaptic and postsynaptic dismantling takes place through different mechanisms and that the postsynaptic side plays an instructive role in synapse dismantling.
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Metamorfosis Biológica/fisiología , Unión Neuromuscular/crecimiento & desarrollo , Terminales Presinápticos/fisiología , Sinapsis/fisiología , Animales , Animales Modificados Genéticamente , Transporte Axonal/fisiología , Drosophila , Unión Neuromuscular/embriologíaRESUMEN
The intestinal peptides GLP-1 and GIP potentiate glucose-mediated insulin release. Agents that increase GLP-1 action are effective therapies in type 2 diabetes mellitus (T2DM). However, GIP action is blunted in T2DM, and GIP-based therapies have not been developed. Thus, it is important to increase our understanding of the mechanisms of GIP action. We developed mice lacking GIP-producing K cells. Like humans with T2DM, "GIP/DT" animals exhibited a normal insulin secretory response to exogenous GLP-1 but a blunted response to GIP. Pharmacologic doses of xenin-25, another peptide produced by K cells, restored the GIP-mediated insulin secretory response and reduced hyperglycemia in GIP/DT mice. Xenin-25 alone had no effect. Studies with islets, insulin-producing cell lines, and perfused pancreata indicated xenin-25 does not enhance GIP-mediated insulin release by acting directly on the beta-cell. The in vivo effects of xenin-25 to potentiate insulin release were inhibited by atropine sulfate and atropine methyl bromide but not by hexamethonium. Consistent with this, carbachol potentiated GIP-mediated insulin release from in situ perfused pancreata of GIP/DT mice. In vivo, xenin-25 did not activate c-fos expression in the hind brain or paraventricular nucleus of the hypothalamus indicating that central nervous system activation is not required. These data suggest that xenin-25 potentiates GIP-mediated insulin release by activating non-ganglionic cholinergic neurons that innervate the islets, presumably part of an enteric-neuronal-pancreatic pathway. Xenin-25, or molecules that increase acetylcholine receptor signaling in beta-cells, may represent a novel approach to overcome GIP resistance and therefore treat humans with T2DM.
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Polipéptido Inhibidor Gástrico/metabolismo , Péptido 1 Similar al Glucagón/farmacología , Glucosa/farmacología , Neurotensina/farmacología , Animales , Glucemia/metabolismo , Western Blotting , Carbacol/farmacología , Línea Celular Tumoral , Agonistas Colinérgicos/farmacología , Sinergismo Farmacológico , Ensayo de Inmunoadsorción Enzimática , Ayuno/sangre , Femenino , Polipéptido Inhibidor Gástrico/genética , Polipéptido Inhibidor Gástrico/farmacología , Humanos , Insulina/sangre , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neurotensina/sangre , Páncreas/efectos de los fármacos , Páncreas/metabolismoRESUMEN
Fibroblast growth factor 23 (FGF23) plays an important role in the development of chronic kidney disease-mineral bone disorder (CKD-MBD). Abnormally elevated levels of 1,25-dihydroxyvitamin D cause osteocytes to secrete FGF23, which subsequently induces phosphaturia. Recent studies have reported that iron deficiency, erythropoietin (EPO) and hypoxia regulate the pathways responsible for FGF23 production. However, the molecular mechanisms underlying the interactions between FGF23 and anemia-related factors are not yet fully understood. The present review discusses the associations between FGF23, iron, EPO and hypoxia-inducible factors (HIFs), and their impact on FGF23 bioactivity, focusing on recent studies. Collectively, these findings propose interactions between FGF23 gene expression and anemia-related factors, including iron deficiency, EPO and HIFs. Taken together, these results suggest that FGF23 bioactivity is closely associated with the occurrence of CKD-related anemia and CKD-MBD.
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Juvenile hormone (JH) is critical for development, metamorphosis, and reproduction in insects. While the physiological importance of JH has been appreciated for decades, its biosynthetic pathway and molecular action remain poorly understood. Drosophila CG10527 encodes a protein with high homology to crustacean farnesoic acid methyltransferase (FAMeT) that converts farnesoic acid to methyl farnesoate (MF), a precursor of JH, but its in vivo functions remain unclear. Here we report that CG10527 is expressed widely in secondary cells in the male accessory glands, in ovarian follicle cells, and in glial cells in the nervous system. Furthermore, CG10527 is expressed abundantly in the corpora allata where JH is synthesized. To understand the physiological functions of CG10527, we generated specific CG10527 deletions. Phenotypic analysis showed that CG10527 null mutants are fully viable and fertile in both sexes, indicating that CG10527 is not essential for survival and fertility. Surprisingly, CG10527 mutants showed no defects in the biosynthesis of MF and JH. However, CG10527 mutants were 3-5 times more resistant than wild-type flies to topically applied MF and JH as well as the JH analog methoprene at both sub-lethal and lethal doses. Taken together, our data indicate that Drosophila CG10527 plays little, if any, role in JH biosynthesis but may participate in the JH signaling pathway.
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Drosophila melanogaster/efectos de los fármacos , Hormonas Juveniles/farmacología , Metopreno/farmacología , Animales , Drosophila melanogaster/genética , Femenino , Eliminación de Gen , Hormonas Juveniles/biosíntesis , Masculino , Sistema Nervioso/metabolismo , Neuroglía/metabolismo , Folículo Ovárico/metabolismoRESUMEN
In this study, we developed novel complex nanoparticles as carriers for curcumin (Cur) delivery by using soy protein isolate (SPI) and cellulose nanocrystals (CNC) as polymer matrices. We found that the SPI-to-CNC mass ratio influenced the stability and physical properties of the SPI-CNC complex nanoparticles. Moreover, SPI-CNC complex nanoparticles had a relatively small size (197.7⯱â¯0.2â¯nm) and low polydispersity index (0.14) at a 6:1 mass ratio. The nanosystem was relatively stable at different pH values (3-9), temperatures (30-90⯰C), and salt concentrations (0-40â¯mmol/L). Furthermore, the complex nanoparticles exhibited a high encapsulation efficiency (88.3%) and sustained release during simulated gastrointestinal digestion. Therefore, SPI-CNC complex nanoparticles are a promising delivery system for hydrophobic bioactive compounds.
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Celulosa/química , Curcumina/química , Nanopartículas/química , Proteínas de Soja/química , Celulosa/farmacología , Curcumina/farmacología , Portadores de Fármacos/química , Portadores de Fármacos/farmacología , Composición de Medicamentos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas/efectos de los fármacos , Tamaño de la Partícula , Glycine max/químicaRESUMEN
Zinc (Zn), as an essential trace element, has been approved to serve many roles in diabetic studies. Also Zn deficiency will aggravate renal damage in diabetes through suppression of nuclear factor-erythroid 2-related factor 2 (Nrf2) expression and function. The purpose of this study was to illustrate the role of Zn in renal apoptosis in diabetes and whether Nrf2 participated in the process. Type 2 diabetes mice model was induced by a single dose of streptozotocin (STZ) injection after high-fat diet (HFD) feeding for 3 months, then the mice were given diets supplemented with different concentrations of Zn (control, 30 ppm; low-concentration, 0.85 ppm). After 12-week treatment, morphology and associated protein expressions were examined. The results showed that low Zn diet significantly aggravated the level of renal apoptosis during diabetes, performed as the upregulation of caspase-3 expression. In addition, either low Zn diet or diabetes or both dramatically decreased the expression of Nrf2 and P-AKT in kidney. Moreover, the expression of ß-catenin in kidney was increased markedly in diabetic groups. Mechanistic study applying human renal tubular epithelial cells (HK11) confirmed the role of Nrf2, as silencing Nrf2 expression abolished Zn supplementation protection against high sugar + high fat + low Zn-induced apoptosis and downregulation of ß-catenin expression. All these results suggest that Nrf2 plays a key role in Zn protection against Type 2 diabetes induced renal apoptosis, which might be through Wnt/ß-catenin signaling pathway.
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Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Vía de Señalización Wnt , Zinc/metabolismo , Animales , Apoptosis , Línea Celular , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Nefropatías Diabéticas/patología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Groundwater contaminated by arsenic endangers our health. Therefore, in this work, a novel composite adsorbent consisting of magnetic chitosan (MCS), zinc oxide (ZnO), and sodium alginate (Alg) was prepared to remove arsenic from groundwater. First, chitosan was coated on the surface of Fe3O4 nanoparticles by coprecipitation. Then, MCS/ZnO@Alg gel beads were fabricated by combining MCS with ZnO and Alg, and crosslinking the composite material in the presence of Ca2+ ions. The MCS/ZnO@Alg beads were characterized by SEM, FTIR spectroscopy, XRD, VSM, and XPS. The adsorption experiments revealed that the MCS/ZnO@Alg magnetic gel beads have high stability and As(V) adsorption capability, and adsorbed As(V) through chemical adsorption. The maximum As(V) adsorption capacity as determined from the Langmuir model was 63.69â¯mg/g. In addition, MCS/ZnO@Alg exhibited good recyclability and high sustainability. This work proves that the MCS/ZnO@Alg gel beads are an ideal candidate for addressing the grievous environmental threats caused by water pollution.
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Alginatos/química , Arsénico/química , Arsénico/aislamiento & purificación , Quitosano/química , Imanes/química , Microesferas , Óxido de Zinc/química , Adsorción , Geles , Concentración de Iones de Hidrógeno , Cinética , Temperatura , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
In this study, a MT(Al)/calcium alginate [MT(Al)@CA] microsphere structure was prepared using sodium alginate (SA) and MT(Al). In order to achieve [MT(Al)@CA] microspheres with a high stability and chemical resistance, glutaraldehyde was used as the crosslinking agent to graft the microspheres and ethylenediamine (ED) into a new type of ED-functionalized MT(Al)@CA microsphere structure similar to a core-shell-type structure [MT(Al)@CA-ED]. This core-shell/bead-like structure was characterized and analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The adsorption performance of the core-shell/bead-like structure for As(V) in solution was studied. The effects of the initial As(V) concentration, reaction time, pH, and different reaction temperatures on the reaction process were studied. The results indicate that at a pH of 4, the removal rate of As(V) by the core-shell/bead-like MT(Al)@CA-ED could reach 94.85% after 150â¯min. The adsorption process is highly consistent with the Langmuir isotherm model (R2â¯=â¯0.9983) and pseudo-second-order kinetic model (R2â¯=â¯0.9973). The maximum adsorption capacity could reach 61.94â¯mg/g. Regeneration experiments showed that the adsorption efficiency of As(V) after six cycles was >80%.
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Alginatos/química , Arsenicales/química , Bentonita/química , Etilenodiaminas/química , Iones/química , Microesferas , Adsorción , Concentración de Iones de Hidrógeno , Análisis Espectral , Temperatura , Contaminantes Químicos del Agua/químicaRESUMEN
The performance of Fe3O4/attapulgite (APT) nanoparticles in Pb(II) adsorption from aqueous solutions could be improved by modifying the particles with aminopropyltriethoxysilane (APTS) and then combining with chitosan (CS) into beads. After preparing the APTS-Fe3O4/APT@CS beads, their surface morphology and crystal phases were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The magnetic properties of APTS-Fe3O4/APT@CS were studied by a vibrating sample magnetometer, while their heat resistance and stability were characterized by thermal weight analysis. A recycling test and comparison of adsorption capacities were also carried out. The adsorption capacity of Fe3O4/APT was improved by the modification with APTS and CS. The adsorption process conforms to the pseudo-second-order kinetic and Langmuir adsorption isotherm models. The adsorption of Pb(II) reaches a maximum of 625.34â¯mg/g, which compares favorably with other reported adsorbents. The results show that APTS-Fe3O4/APT@CS is a promising hybrid adsorbent for effective removal of Pb(II) from water.
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Quitosano/química , Hidrogeles/química , Plomo/química , Plomo/aislamiento & purificación , Compuestos de Magnesio/química , Propilaminas/química , Silanos/química , Compuestos de Silicona/química , Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Nanopartículas de Magnetita/química , Nanocompuestos/química , Soluciones , Temperatura , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del AguaRESUMEN
We previously demonstrated that infusion of an intestinal peptide called xenin-25 (Xen) amplifies the effects of glucose-dependent insulinotropic polypeptide (GIP) on insulin secretion rates (ISRs) and plasma glucagon levels in humans. However, these effects of Xen, but not GIP, were blunted in humans with type 2 diabetes. Thus, Xen rather than GIP signaling to islets fails early during development of type 2 diabetes. The current crossover study determines if cholinergic signaling relays the effects of Xen on insulin and glucagon release in humans as in mice. Fasted subjects with impaired glucose tolerance were studied. On eight separate occasions, each person underwent a single graded glucose infusion- two each with infusion of albumin, Xen, GIP, and GIP plus Xen. Each infusate was administered ± atropine. Heart rate and plasma glucose, insulin, C-peptide, glucagon, and pancreatic polypeptide (PP) levels were measured. ISRs were calculated from C-peptide levels. All peptides profoundly increased PP responses. From 0 to 40 min, peptide(s) infusions had little effect on plasma glucose concentrations. However, GIP, but not Xen, rapidly and transiently increased ISRs and glucagon levels. Both responses were further amplified when Xen was co-administered with GIP. From 40 to 240 min, glucose levels and ISRs continually increased while glucagon concentrations declined, regardless of infusate. Atropine increased resting heart rate and blocked all PP responses but did not affect ISRs or plasma glucagon levels during any of the peptide infusions. Thus, cholinergic signaling mediates the effects of Xen on insulin and glucagon release in mice but not humans.
Asunto(s)
Glucagón/metabolismo , Intolerancia a la Glucosa/sangre , Insulina/metabolismo , Neurotensina/farmacología , Polipéptido Pancreático/metabolismo , Receptores Colinérgicos/metabolismo , Transducción de Señal , Adulto , Atropina/administración & dosificación , Atropina/farmacología , Glucemia/metabolismo , Estudios Cruzados , Femenino , Polipéptido Inhibidor Gástrico/administración & dosificación , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Secreción de Insulina , Masculino , Persona de Mediana Edad , Neurotensina/administración & dosificaciónRESUMEN
Hyponatremia is a common condition encountered in clinical practice. A number of studies have associated low serum sodium levels with increased mortality in various patient populations, such as hospitalized patients and patients with various comorbid conditions; recent studies have shown that individuals with chronic kidney disease also are afflicted by hyponatremia. However, few studies have focused on patients with hemodialysis. Evidence supporting the incidence and prevalence of hyponatremia, clinical characteristics and the association with patient outcomes with hemodialysis is limited. In the present review, we examined the physiology and pathophysiology of water and sodium balance with a special emphasis on changes occurring during end-stage renal disease. The outcomes in patients undergoing hemodialysis were associated with low serum sodium. We evaluated the associations between hyponatremia and mineral bone abnormalities and discussed the elevated incidence and prevalence of difficult clinical outcomes associated with hyponatremia. We also provided specific recommendations for hemodialysis treatment in hyponatremic patients.
Asunto(s)
Hiponatremia/etiología , Diálisis Renal/efectos adversos , Insuficiencia Renal Crónica/complicaciones , Humanos , Hiponatremia/sangre , Insuficiencia Renal Crónica/mortalidadRESUMEN
OBJECTIVE: To evaluate the parathyroid function in maintenance hemodialysis patients from 4 hemodialysis centers and to analyze the cause of the dysfunction. METHODS: This cross-sectional study included patients with chronic renal disease undergoing maintenance hemodialysis treatment at 4 hemodialysis centers in Changchun, China, between March 2014 and August 2015. A total of 337 patients were asked to complete a questionnaire including their name, gender, age, hemodialysis duration, the use of calcium carbonate and vitamin D3 supplements, health education status, hemofiltration frequency, appetite, and education level. Serum intact parathyroid hormone (iPTH), phosphorus, total calcium, blood urea nitrogen (BUN), and creatinine (Cre) levels were obtained from clinical information. Patients with iPTH data were divided into 2 groups: Normal group: the patients with an iPTH level < 100 pg/ml (28 subjects); Abnormal group: the patients with an iPTH level > 100 pg/ml (136 subjects). Intergroup differences were analyzed using the t-test. The enumeration data were analyzed by the χ2 test. RESULTS: The iPTH levels were not monitored for 173 maintenance hemodialysis patients (51.3%) but for 164 patients (48.7%). Of the 164 patients, 28 (17.1%) had a normal serum iPTH level, while the other 136 (82.9%) had an abnormal iPTH level. The maintenance hemodialysis duration and phosphorus levels in the Abnormal group were higher than those in the Normal group (P < 0.05). The appetites of patients in the Abnormal group were better than those of patients in the Normal group (P < 0.05). CONCLUSIONS: A lower proportion of patients on hemodialysis had a normal iPTH level. The phosphorus levels of patients on hemodialysis should be controlled via dietary interventions.